Three men have been crushed in a workplace accident at the site of the $1 billion high-rise Jewel development on the Gold Coast.

The CFMEU said the accident happened about 8:45am when a steel tray carrying electrical cables collapsed.

Queensland Ambulance's Gavin Fuller said the three men, aged 27 and 28, were working in a lower car park of the building when the cabling conduit fell two-and-a-half metres onto them.

"One of the workers was trapped. His co-workers have been able to remove that [the conduit], which was quite good considering it weighs about 80 kilograms per metre so it certainly minimised his injuries," he said.

"The other two workers were struck by it but not trapped underneath it."

Mr Fuller said one of the workers likely had a fractured pelvis, while another had a leg and shoulder injury.

The third man also had a shoulder injury, he said.

All three have been taken to Gold Coast University Hospital in a stable condition.

"Three workers were working below a bit of electrical cable tray carrying a fair bit of weight … big thick electrical cables … and the tray has given way where the dyna bolts go into the wall and it has crushed three workers," he said.

He said workers were concerned because similar cabling would likely be throughout the development.

"They are probably going to have to check all of that to make sure that … there are no problems with the bolts that were holding up that tray, because this is a very serious incident," Mr Vink said.